1. Technical Field
The present invention relates to data queue management within a network in general, and in particular to an apparatus for managing distributed data queues within a network.
2. Description of Related Art
Demands for high-performance on-board processing are increasing due to large amount of data stemmed from improvements in sensor resolution, sensor bandwidth and the number of sensors integrated into a single platform. New processing capabilities are being introduced through field programmable gate arrays, digital signal processors and multi-core general purpose system-on-chip processors. Along with the improved on-board processing throughput, higher performance communications network infrastructure at the chassis backplane and local-area network (LAN) levels is being developed to transport data. However, improved sensors and groups of sensors can still generate data at rates that far exceed the instantaneous data processing and/or off-board communications rates provided by a platform such as a spacecraft.
For example, current spacecraft typically use MIL-STD-1553B bus (1 Mb/s), SpaceWire (less than 400 Mb/s) and/or peripheral component interface (PCI) bus (1 Gb/s to 2 Gb/s) to handle intra-subsystem or LAN communications across a backplane. The data rates provided by the above-mentioned interfaces are generally not sufficient to support on-board processing needs for systems in new spacecraft.
Next Generation Spacecraft Interconnect Standard (NGSIS) standardization efforts under AIAA, RapidIO and VITA standards umbrellas have developed SpaceVPX (VITA 78) standard, which defines a fault-tolerant version of OpenVPX® (VITA 65) suitable for high performance backplanes in space applications. SpaceVPX employs RapidIO data plane, SpaceWire control plane and I2C utility plane in either a mesh or switch connected backplane structure, which can support aggregate bandwidth exceeding 200 Gb/s. Combined with RapidIO LAN for inter-subsystem communication, the above-mentioned new standard provides the framework for dramatic increases in on-board communications bandwidth needed to support high data rate sensors and tera-FLOPS processing capability. While such on-board processing capability helps to reduce communications bandwidth requirements between downstream processing elements or downlinks, the resulting processed data and required supporting raw data can still exceed the processing capability and/or downlink bandwidth available. Thus, there is a need to provide data storage, rate controlled delivery of stored data to communications links and selection of the data to be delivered based on priority and time of arrival.